Illuminating attachment for sights for ordnance.



PATENTED JULY 2. 1907'.

` G. N. SABGMULLBR.

ILLUMINATING ATTACHMENT PoR sIGHTs PoR ORDNANGE.

APPLIATI'ON FILED APR. 9. 1907.

.UNITED STATES PATENT oEEIcE.

- ILLUMINATING ATTAcmNT Fort srems son onDNaNcE.

`Speciica'tion of Letters Patent.

Patented July 2, 1907.

i `.Application filed April 9. 1907i Serial No. 367,237.

To all whom it may concern: p

` Be it known that I, GEORGE NICHOLAS SAEGMULLER; a citizen of the United States; residing at Rochester', in the county of Monroeand State of New York, have invented certain new and useful Improvements in Illuminating Attachments for Sights for Ordnance; and l do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to` which it appertains to make and use the same.

This invention consists in an illuminating attachment intended to be used at night with gun sight telescopes ofl that class which have reticules composed of glass or other refracting material with cross lines etched therein, or which have'simple crossl hairs or wires, used in the ordinary-way.

The purpose of the invention is to illuminate a portion'of the cross lines drawn or etched on the surface of glass in a compound cemented lens of a sight telescope, or to illuminate the wires or cross hairs themselves.

The invention hereinafter described is intended toA provide certain improvements over that showny in the application of Henry C. Mustin and lGeorge N. .Saegmullen improvements in sights for ordnance, filed April'l?, 1906, Serial No, 312,212.l

The object of the invention can be explained by pointing ont the defects in other devices for illumination. For example, there is one which consists in placing in the eye piece of a telescope a glass reticule with parallelplane facesyonone of these faces cross lines are etchedl The periphery of the reticule is polished and silvered except for a`small portion where a pencil of light is admitted to the interior; the rays of light entering the interior illuminate a portion of the cross lines directly!v and illuminate the other portions indirectly after sucpessive reflections at the cylindrical mirror formed by theI periphery of the reticule. The complete cross lines are thus rendered visible; but besides the light scattered from the cross lines there is. light from the caustics which are necessarily formed within the field, by refiection at the cylindrical surface of the periphery of the reticule; also there is light scattered 'from dust, or any inequalities on the faces of the reticule. All of this light is additional -to the light emitted by thel target or other object under observation; now it is well known that when an observer is looking at a dimobject, all luminous surfaces between the object under observation .and his eye are seriousy hindrances tohis ability to see the object. But, in order that the line of sight may be directed to the target,

the observer must be able to see the intersection of thefcross lines, so there must be at least a-suflicient amount of light for that purpose interposed between his eye and the target. In the case cited, there is v added to this amount, 'a comparatively large quantity whichis certain to be ,givenvby the caustics. The same defect appears in another type of illuminating device in which, instead of a reticule, there is a compound cemented lens, on one of whose cemented faces are etched the cross lines. The periphery of this compound lens ispolished andsilvered except for a small portion where the pencil of light is'admitted to illuminate the cross lines; thev caustics by reilection'at a cylindrical surface are therefore'formed within the iield of this telescope also, and thusthe4 -observers ability to direct the line of siglit to a dim target is seriously hindered. It is evident thatthe eiiciencyof a 'night sight telescope will be a maximum when the intensity of light from luminous surfaces interposed between the eye and the'obj ect under observation is reduced to a minimum. To this end itis necessary to remove the caustics and to lrestrict the illuminated arearof the line to only that portion of them that is required for directing the line of sight. Now in order that the line of sight may be directed,

it is necessary, as stated above, for the vobserver to distinguish the intersection of the cross linesfthe vicinity of the intersection must therefore be given a certain intensityof illumination per unit of area. Heretoiore it has been the practice to give `the` cross linesbr, in other types, to the-cross wires or hairsy a uniforim illumination over all rparts of them that appear in the field. Now if vthe illumination per unit of area is kept constant, and the area illuminated be restricted to,` the vicinity of the intersection, the ability 'of thebbserver to direct the line of sight will not be interfered' with, but the total quantity of light sent from the lines to the observers eye will be 'diminished.

The object of the invention, therefore, is tolilluminate -a very` small portion of the intersection of the cross lines, without producing in the `field of the telescope any caustics or luminous areas that would be amately parallel rays of light from the rear, is thrown on the rear face of the field lens at such an angle that the axis of the pencil, after refraction at this face, makes as small an angle with the axis of the eye piece as is practicable. The direction of the pencil, inside the ield lens, is such that its path crosses and thus illuminates the intersection of the cross lines. The

pencil after emergence from the iront face ofthe field lens proceeds to a portion of the telescopetube that is obscured from the eye of the observer. There is of course a partial reflection at, the rear face of the `field lens where the pencil enters; but these partially relccted rays proceed to a recess i n the tube which is obscured from the eye oi the observer. The partial reflection at the iront face of. the field lens when the pencil emerges, is negligible for the incident light is very nearly normal to the surface at this point. ln consequence of this arrangement only a small amount olight is thrown on the intersecting lines, and this light is sufficient only for the purpose of illuminating the vicinityl of the intersection oi those lines, and it doesnotisubsequently appreciably affect the clear* `ness, of the object,

` This invention will be understood by reference to the accompanying drawings in which' the same parts are indicated by the saine letters throughout the several views.` l

Figure l shows a central vertical section through' the ey'erpiecel end of the lsight telescope, and shows the illuminating attachment, partly in section and partly in. elevation. Fig. 2 shows a cross section along the line 2 2 o- Fig.` 1. Fig. 3 is a detaii showing the exterior of the adjustable prism holder, and Fig. if

shows a section through the 1axis of the prism holder` shown in Fig. 4.

ln the drawings the eye piece end of the telescope only is shown, as the other parts oi the telescope are well known in the art and do not constitute a part oi this invention.

A represents the main telescope tube in which is mounted the sleeve B, which -carres the compound eld lens which is composed of the plane glassplate C cemented to the lens C2. Etched on the face 0f this plate C or on the face o the lens C2, where the two faces abut, arethe ordinary intersecting lines, which correspond to cross'hairs. These lines are well known and are not shown in the drawings.

To Vkeep* the outer surface of the plate and lens free from dust, openings a and b0 are provided, which `are closed by suitable shutters a and b. These shutters may be removed and the face of the lens or plate may be brushed oft with a' suitable brush inserted through the opening; thus, whenever necessary, the field lens may be'cleaned without disturbing the optical adjustment of the telescope, and withoutdisturbing therelation between the axis oi the bore of rthe gun and the line of sight.

The compound lenses E and' E which compose the eye lens combination are mounted in the ring D, which is screwed into the sleeve B.

So far as described, the optical parts are all old, and the invention consists in applying to these old parts the improved illuminating device which will now be described. Y p

F represents a socket piece, which is attached to the telescope tube A over the opening ii in the sleeve B. This socket piece has two hollow arms F and F2, ixed at right angles to each other, which form holders for the adjustable prism holder H, and for the lamp socket G, which is connected by the wires g in the cable G to the sourcc'o electricity, not shown. This lamp socket G carries a small incandescent lamp G2. This stairs holder F2 is provided with lugs f to engage the clamp screw I, which is operated by the milled head l, and thus the socket-G is adjustably clamped in its holder. Suitable Ventilating holes fo are. provided to prevent excessive heating, While ther current is on the lamp. The; lamp socket may be moved in or out and clamped at the desired position inthe holder F2, whereby the amount oi light thrown on the cross lines may be varied, as desired.

H represents the prism holder, which consists of a vsubstantially spherical body portion hollowed out,

as at- H", see Fig. 4, and with a cylindrical projecting 'arm H at one side of the body portion, and with a `hollow projecting arm H2 at therother side. This latter` arm is closed by a screw cap H" having the axial perforation h in line with the perforation h at one side of the prism chamber.- The prism P and its metal support P, are held in place in the prism chamber H by means oi 'the screw cap H3. The spherical portion of the prism holder H is seated, as at f, in the socket piece F, and is also seated on a suitable bearing in the annular screw cap N, ,which is screwed into the arm F of the socket piece. A second screw cap K is alsov screwed into this socket piece, carrying 1a series of screws K, which latter bear against the cylindrical arm H of the prism holder E, and by means oi these screws the axis of the prism holder may be adjusted with extreme accuracy.

Oneot the outer faces of the prism P is ground so as to give the effect of a ground source of light. Light from the lamp G2 enters the prism P and is reflected, and the rays made parallel by means of theplanoconvex lens Q, whose focal length equals the distance from the ground side of the prism to the plane side oi lens, in the direction L, ,whence it is retracted in the direction L by the compound lens, and emerges from said lens in the direction L2, and strikes the side oi the telescope out of the range of vision of the observer. That part of the light which is reflected from the face of the compound lens passes downward in the dire@ tion L0 and enters the recess b2, thus reaching the side o the telescope out ol the range of vision of the observer.

It will. be seen that only so much of the light fromv the lamp as'can pass through the openings h and h, can enter the telescope, and that by adjusting the axis of the prism holder this pencil of rays may be caused to illuminate a limited portion only of the compound lens, and this light is then retracted in line substantially with the line of sight, thus not materially intcrtering with the vision of the observer. Thus a small part only ot the field lens is illuminated, and by conining this part to the intersection of thc cross hairs or lines,`as already described, the illumination is so small as not to materially impair the ability of the observer to observe faint objects.

Bygrinding one face of the prism P, the light is softened and made more uniform, and the lamp socket may be moved in or out, thus varying the intensity of the illumination thrown on the iield lens, but without making it material in what particular plane the filament ofthe lamp is located..

As these small lamps require frequent renewals, if

the ground glass source o light were omitted, and

intensity oi the illumination thrown on the-lens would not only vary with the distance of the lamp,

from thel prism, but might also vary very materially, according to the exact position of the filament with regard to the axis of the illuminating attachment. By having the prism holder arranged with a ball andy cross lines etched into a compound lens, it. will be i ,obvious that the ordinary cross hairs or cross wires may be substituted for these lines Without departing from the spirit of my invention. It will also be ob-y vious that various other modifications might be made, which could be used 4without departing from the spirit of the invention.

Having thus described `my invention, what l claim and desire to secure by Letters Patent oi the United States, is

" mounted on said telescope with itsxaxis at an angle to the line of sight, and having an axial perforationtherein, a source of light mounted at one sider of said prism holder, and a prism mounted in said holder` and adapted to reflect a ypencil of rays of light from said source of light through said axial perforation, substantially as described.

2. In an illuminating attachment for ordnance sights, the combinationrwith a telescope provided with a reticule having cross lines, of a socket piece secured to said telescope in rear of said reticule, and having two hollow arms at right angles to each other, an incandescent electric -lamp mounted in one of said arms, a prism holder mounted in the other hollow arm and havingvan axial perforation opening into the interior of the telescope at an angle with the line of sight, and a right angle prism mounted in said, prism holder and adapted to vreflect a pencil or rays of light'from said electric lamp through said axial perforation, substantially -as described.

3. In an illuminating attachment for ordnance sights, the combination with a telescope 'provided with a reticule having cross lines, of a socket piece secured to said telescope in rear of said reticule, and having two hollow arms at right angles toeach other, an incandescent electric lamp mounted in one of said arms, a prism holder mounted adapted to reilect a pencil of rays of light from said electricv lamp through said axial perforation, and a lens mounted in lsaid prism holder substantially as described. 4. In au illuminating attachment for ordnance sights,

I the combination with a telescope provided with a reticule having cross lines, of a socket piece secured toV said telescope in .rear of said reticule, and having two hollow arms at right angles to each other, an incandescent: electric lamp mounted in one ot said arms, a prism holder mounted in the other hollow arm and having an axial 'perforation opening into the interior oi.' the telescope at an angle with the line of sight, with a right angle prism mounted in said prism holder and adapted to reect a pencil of rays of light .from said electric lamp through said axial perforation, and means for adjusting the axis of said prism holder, and a. lens mounted in said prism holder substantially as described. v, y

5. In an illuminating attachment for ordnance sights, the combination with a telescope provided with a reticule having cross lines, Iof a socket vpiece secured to said telescope in rear of said reticule, and having two hollow arms at right angles to each other, an incandescent electric lamp adjustably mounted in one of said arms, a prism holder mounted in the other hollow arm and having an'axial perforation opening into the interior of the telescope at an angle with the line of sight, and a right angle prism mounted in said prism holder and adapted to reect a,pencil of rays of light from said electric lamp through said axial perforation, and a lens mounted in said prism holder sub- -stantially as described.l

6. In an illuminating attachmentfor ordnance sights, the combination with a telescope having a reticule provided Wth cross lines, of an adjustable prism holder vmounted on said telescope with its axis at an angle to the line of sight, and having an` axial perforation therein, a -source of light mounted at one side of said prism holder, and a prism having one of its faces ground mounted in said h older and adapted to'reiiect a. pencil of rays of light from said source of light through said axial perforation, substantially as described.

7. In an illuminating attachment for ordnance sights, the combination with a telescope provided with a reticule having cross lines, of a socket piece secured to said telescope in rear of said reticule, and having two hollow arms at an angle to each other, an incandescent electriclamp mounted in one of said arms, a spherical prism holder provided with axially extending arms mounted in bearings in the other hollow arm-and having an axial perforation in one of its arms opening into the interior of the telescope at an angle with the line of sight, adjusting screwsengaging one of the arms of said prism holder, and a prism mounted in said prism holder and adapted to reflect a pencil of rays of light from said electric lamp through said axial perforation, substantially as described,

8. In an illuminating 'attachment for ordnance sights, the combination with a telescope provided with a reticule having Na compound lens with cross lines etched therein, of a socket piece secured to said telescope in rear of said reticule, and having two hollow arms at an angle to each other, an incandescent electric lamp mounted in one of said arms, a prism holder mounted in the other hollow arm and having a perforation opening into the interior of the telescope -at an angley with the line of sight, with a prism, having one of its outer faces ground, mounted in said prism holder and adapted to reflect a pencil of rays of light from said electric lamp through said` axial perfoi-ation, substantially' as described.

9, In an illuminating attachment for ordnance sights, the combination with a telescope provided with a reticule having a compound lens with cross lines etched therein, of a socket piece secured to said telescope in rear of said reticule, and having two hollow arms atA an angle'to each other, an incandescent electric lamp mounted in one ot said arms, a prism holder mounted in the other hollow arm and having a perforation opening into the interior of the telescope at an angle with the line of sight, with a prism i mounted in said prism holder and 'adapted to reilect a pencil of rays of light from said electric lamp through said perforation, and means for adjusting the axis of said prism holder, and a lens mounted in said prism holder substantially as described.

In testimony whereof, I afiix my signature, in presence of two witnesses.

GEORGE NICHOLAS .SAEGMULLER.' Witnesses:

Faun W. BET'rlN, Gnoaen H. Lnrrnnn. 

